352 THE EAR
or along the sheath of the cochlear nerve. Spread to the posterior fossa
may result in a cerebellar abscess.
CLINICAL FEATURES. During the stage of fistula formation there are attacks
of dizziness and occasional vomiting, especially on stooping or turning
quickly. Spontaneous nystagmus may or may not be present and, if elicited,
may be to either side. The patient tends to fall to the healthy side. On
examination of the ear cholesteatoma is usually seen and a fistula sign is
Fig. 180. Vertical coronal section through vestibule in case of chronic middle ear suppuration, with
obliteration of tympanic cavity. The labyrinth was infected through the lateral canal. The pathological
condition is one of latent labyrinthitis. 1, Vestibule filled with granulation and fibrous tissue; 2, Facial
nerve partially surrounded by connective tissue—the bony wall of the facial canal has been eroded; 3,
Cystic space in attic; 4, Caries of promontory; 5, Perforation of drumhead; 6, Tympanic cavity almost
obliterated by new connective-tissue formation; 7, Round window membrane incorporated in new
connective tissue; 8, Jugular bulb; 9, Footplate of stapes.
present. Hearing is reduced, although not severely, and the caloric reaction
In serous labyrinthitis there may be pain, tinnitus and increased hearing
loss occasionally, and there will be vertigo, vomiting and loss of balance
with a sensation of objects moving from the diseased to the healthy side.
At times the patient feels as if he were turning. If he is in bed he lies on his
healthy side and looks towards the diseased side as this reduces the vertigo.
There is spontaneous nystagmus, in the earliest stages to the affected side
and later to the sound side. The fistula sign is usually absent and the caloric
reaction is diminished. As a rule there is no pyrexia.
The purulent phase is short lived and unassociated with fever, unless
there is an intracranial complication. Giddiness is intense and nausea and
vomiting are frequent. There is marked spontaneous nystagmus to the
healthy side, while spontaneous pointing and falling are to the diseased
side. The membranous labyrinth is destroyed so that there is no fistula
sign, no response to caloric testing and complete deafness.
TREATMENT, The discovery of a fistula sign on examination is evidence
that cholesteatoma has eroded the labyrinth. This may be confirmed on
radiography or tomography, and it is an indication for radical mastoid
surgery. When an acute infection supervenes with the production of a serous
labyrinthitis treatment is a full course of antibiotics with surgical interference
by myringotomy or mastoidectomy if this is indicated. The further develop-
ment of purulent labyrinthitis calls for antibiotic therapy in large doses in
the hope of preventing destruction of the membranous labyrinth. Should